Genesis-Plus-GX/source/ngc/vfat/diskio.c
ekeeke31 fb745c3b0a
2007-08-20 09:45:09 +00:00

100 lines
2.5 KiB
C

/****************************************************************************
* FAT16 - VFAT Support
*
* NOTE: Only supports FAT16 with Long File Names
* I have no interest in adding FAT32
*
* Reference Documentation:
*
* FAT: General Overview of On-Disk Format
* Version 1.02 May 05, 1999
* Microsoft Corporation
*
* FAT: General Overview of On-Disk Format
* Version 1.03 December 06, 2000
* Microsoft Corporation
*
* This is targetted at MMC/SD cards.
*
* Copyright softdev 2007. All rights reserved.
*
* Diskio Module
* -------------
*
* This module is almost identical to the one found in ChaN's TinyFAT FS.
* It's a logical abstration after all :)
*
* This covers stdio file on a SD image file
****************************************************************************/
#include <gccore.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sdcard.h>
#include "vfat.h"
/* Not so public exports from card_io.c */
#define MAX_DRIVE 2
extern u8 g_CID[MAX_DRIVE][16];
extern u8 g_CSD[MAX_DRIVE][16];
extern u8 g_CardStatus[MAX_DRIVE][64];
extern s32 card_initIO(s32 drv_no);
extern s32 card_readSector(s32 drv_no,u32 sector_no,u8 *buf,u32 len);
extern s32 card_writeSector(s32 drv_no,u32 sector_no,const void *buf,u32 len);
extern s32 card_readStatus(s32 drv_no);
#define CARDIO_ERROR_READY 0
/* End of not so public exports */
/****************************************************************************
* DISKIO_Init
*
* Initialise communication with the disc
****************************************************************************/
int DISKIO_Init( int drive )
{
int res;
if ( drive < 0 || drive > 1 )
return FS_ERR_PARAM;
res = card_initIO( drive );
if ( res == CARDIO_ERROR_READY )
return FS_SUCCESS;
return FS_ERR_IO;
}
/****************************************************************************
* DISKIO_ReadSectors
*
* Read sectors from the disc
****************************************************************************/
int DISKIO_ReadSectors( int drive, void *buffer, int sector, int count )
{
int res = -1;
int i;
int bytes = 0;
if ( drive != 0 && drive != 1 )
return FS_ERR_PARAM; /* Must be 0 or 1 */
/* libOGC appears to only read in single sectors */
for( i = 0; i < count; i++ )
{
res = card_readSector( (int)drive, sector + i, buffer + bytes, SECTOR_SIZE);
if ( res != CARDIO_ERROR_READY )
return FS_ERR_IO;
bytes += SECTOR_SIZE;
}
if ( res == CARDIO_ERROR_READY )
return FS_SUCCESS;
return FS_ERR_IO;
}